The present invention relates to an optically variable areal pattern and a value document having such an optically variable areal pattern.
Objects to be protected are frequently furnished with an optically variable areal pattern that permits the authenticity of the object to be verified, and simultaneously serves as protection against unauthorized reproduction.
Diffractive relief patterns (holograms) and relief patterns behaving according to ray optics (micromirrors or microprisms) are known.
Through diffraction, diffractive relief patterns produce colors, with the entire color spectrum normally being run through when tilted, or through color mixing, for example for matte patterns, a white color impression being produced.
Relief patterns behaving according to ray optics, on their own, initially deliver colorless depictions. By providing an additional color coating (for example a color-shift coating), colors or also a color change can be produced. Such coatings normally provide, among other things, at a certain viewing angle or glancing angle of the micromirrors, only one color, or a set color change defined by the coating.